Human Populations Limits to Growth：人类的人口增长的极限.ppt

How can we quantify the impact we have? Calculate an Ecological Footprint Model for quantifying the demands that human populations make on their environment The area of land in the same vicinity as the population that would be required to provide for all of the population’s resources and assimilate all of it’s wastes It is the inverse of the carrying capacity Ecological footprints Different Populations, Different Problems Human pressure on the environment caused by three factors I = P x A x T Population size Affluence Technology Ecological Footprints by World Region The average American places at least 20 times the demand on Earth’s resources as does an average person in Bangladesh Fig. 5.7 here Affluence in the United States Consume the largest share of 11 of 20 major commodities Eat more than three times the global average in meat Lead the world in paper consumption Environment improves with increasing affluence Enables wealthy to clean up immediate environment by transferring waste to more distant locations. Affluent isolate themselves and unaware of the environmental stresses caused by their consumptive lifestyles. Calculate a Footprint for a given group Calculations are approximations Total area required is the sum of these two per capita requirements multiplied by total population Footprint Calculation Ignores land and water needed for aquatic and atmospheric resources for the assimilation of waste other than CO2 For production of energy or materials needed to support arable land in an area To replace productive land lost by urbanization and so on Calculate your Footprint / Did you know that the planet takes 1 year and 4 months to regenerate the material that we consume in 1 year We are in an overshoot ? liquidating the earth’s assets Country Comparison LEDC – less economically developed country: a country with low to moderate industrialization and low to moderate average GNP per capita MEDC – more economically developed country: a highly industrial